At around 10:30pm police got a call from the clerk at the Big Apple store on State Street.
He said two robbers were wearing black hooded shirts and handed him a note saying they had a gun and wanted money.
A customer saw them get into a car parked nearby and followed them calling police, who caught up with the car.
20-year-old Tristan Berry of Hallowell and 26-year-old Bobbiejo Lavoie of Pittston have been charged with robbery.
Police say they managed to recover most of the stolen money, and credit the clerk and the customer for helping them make a quick arrest.